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Clues of Life's Origins Found In Galactic Cloud

Posted by samzenpus on from the it's-full-of-stars dept.

astroengine writes "Finding things like amino acids in space directly is a difficult business. So, instead of finding them directly, a team using West Virginia's Green Bank Telescope, led by Anthony Remijan, discovered two other molecules – cyanomethanimine and ethanamine — both of which are precursor molecules. In other words, these molecules are the early steps in the chain of chemical reactions that go on to make the stuff of life. The researchers found these molecules near the center of the Milky Way inside a hulking interstellar cloud known as Sagittarius B2 (Sgr B2), spanning 150 light-years in size, up to 40 times as dense as any other cloud the Milky Way has to offer."

6 of 80 comments (clear)

  1. Hey, wait a sec... by ibmleninpro · · Score: 5, Informative

    I recognize this story...
    I'm on one of the graduate students on this project! Feel free to ask me anything if you're interested!
    Since the article didn't post a link to the paper (my #1 pet peeve as a scientist), here it is on arxiv: http://arxiv.org/abs/1302.0909

    1. Re:Hey, wait a sec... by rusty0101 · · Score: 5, Informative

      It's not just finding amino acids. Yes, as yous say amino acids are have been detected before. the problem is that there are a lot of different amino acids, and only some of them are essential to the fundamental building blocks of life. What this research is showing is that they have detected some of the essential amino acids, rather than the general variety known about before. It's somewhat like the difference between knowing that there is carbon in interstellar space, and finding diamonds, graphine or bucky-tubes. Knowing that there is carbon there does not imply that you will find one of the specific forms, but if you find one of those forms, you can deduce that it is much easier to start from there as a building block for other things (presuming you know things that use them as building blocks.)

      Likewise just because the building blocks of life are in interstellar space doesn't mean that life is everywhere, just that when conditions are favorable, it's reasonable to presume that the amino acids necessary can show up.

      --
      You never know...
    2. Re:Hey, wait a sec... by Anonymous Coward · · Score: 5, Informative

      The radio telescopes that are used technically do record a full "column" of signal in the path between here and the molecular cloud. They key is we assume the atmosphere is relatively uniform across the time of the measurement so the telescope actually moves and points away from the source to collect a "background". This allows us to remove any signal coming from the atmosphere.

      Additionally we can see the temperature these molecules are at. For this example the molecule is only sitting at a few K which is far too cold to be in the earths atmosphere (even the upper atmosphere).

    3. Re:Hey, wait a sec... by ibmleninpro · · Score: 5, Interesting

      I'm not one to really speculate on this, since I'm a spectroscopist, not an astrobiologist, but I'll give it a shot. There is a BIG difference chemically (and temporally) between what we detect in clouds in star-forming regions and what we detect on comets or any kind of interstellar surface. There's definitely a cause-and-effect thing going on here, but the real gap in knowledge is what's the mechanism to go from cloud consitutents to cometary material (then obviously to planetary surfaces).

      What's really interesting in the context of chemistry is the chemical or physical mechanism for generating complex molecular substance in an early protoplanetary system (either in a cloud, or a disk around a young star, or whatever). We can't really attempt to recreate the conditions of space -- we can do cold, we can do fairly low pressures (though obviously not as low as interstellar space), we can make stuff on surfaces, we can even bombard it with an intense and high-energy photons -- but it's mostly just simple models for the intense conditions of a star forming region.

      Most of the research does point to the conclusion that most of the complex organic material gets formed on surfaces of various ices or grains -- it's really the only thermodynamically viable way of forming stuff at such extreme conditions. But how do we probe this spectroscopically? It turns out spectroscopy on surfaces kind of sucks (no offense to surface scientists) -- the absorptions are broad and fairly uncharacteristic, especially on a surface with a potentially complex mixture of molecules of both high and low abundance. It turns out the best way to get resolution is to go to gas-phase. Problem here is that it's damn cold! Complex stuff can't get formed sub-20 K temperatures. But we do see stuff, like this molecule, that give us some sense of what's really going on. There's no way to detect whether or not this stuff is being made on ices or grains and then getting heated off by the absorption of a photon, or whatever, but it's likely the case (especially since there is experimental evidence of ethanimine and cyanomethanimine being formed on cold ice surfaces).

      Amino acids (and nucleic acids) might be a lot more abundant than we know. But it's likely this stuff sticks to the ices and grains, or gets formed a lot later in the star formation cycle. That being said, finding these molecules that are studied precursors to major biomolecules is a good sign that the field's on the right track (for the most part. There's a lot of old ideas in the field, and with the advent of the next generation of radio astronomy starting this decade, I think we'll start to see a lot more results like this).

    4. Re:Hey, wait a sec... by ibmleninpro · · Score: 5, Interesting

      I should also add that it's possible to even map out a molecule's "location" in a region of space. We've done some work with spatially-resolved studies of nitrile-containing molecules (which is where these discoveries came out of) where you can see the specific regions of the cloud where these molecules are most abundant. You can learn a ton about the formation of these molecules from this, since the cloud is actually quite a chaotic beast -- there are cold patches, like temperatures below 20 K, then there are patches where the temperature is 100 K or even more. The chemistry is very drastically different in each of these areas, and learning about which molecules show up where tells us a ton about molecular formation processes in a star-forming region.

  2. Fermi Paradox by dcmcilrath · · Score: 5, Interesting

    The Fermi Paradox, this thing, says that we should not only have encounted "life" by now, but we should have encountered life at least as complex as ours over and over again by now.

    Kinda creepy to think about the endless possibilities out there. To quote Douglas Adams: "Space is big. Really big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space"

    --
    -1 Comment Contains Portal Reference